dom/presentation/PresentationConnection.cpp
author Andrew McCreight <continuation@gmail.com>
Tue, 29 Aug 2017 16:02:48 -0700
changeset 429603 71882fd33c91d06876715d6ac8b37847c8d14726
parent 417235 312f7a5a2c08d394a2403c837e5ee546dd4103d7
child 431418 aad2ab1d510cf39ebb0684aa9e9b15572c6cd73c
permissions -rw-r--r--
Bug 1391005 - Eliminate NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED. r=peterv Replace it with NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION, because it has been the same for a while. MozReview-Commit-ID: 5agRGFyUry1

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "PresentationConnection.h"

#include "ControllerConnectionCollection.h"
#include "mozilla/AsyncEventDispatcher.h"
#include "mozilla/dom/DOMException.h"
#include "mozilla/dom/File.h"
#include "mozilla/dom/MessageEvent.h"
#include "mozilla/dom/MessageEventBinding.h"
#include "mozilla/dom/PresentationConnectionCloseEvent.h"
#include "mozilla/ErrorNames.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/IntegerPrintfMacros.h"
#include "nsContentUtils.h"
#include "nsCycleCollectionParticipant.h"
#include "nsIPresentationService.h"
#include "nsServiceManagerUtils.h"
#include "nsStringStream.h"
#include "PresentationConnectionList.h"
#include "PresentationLog.h"

using namespace mozilla;
using namespace mozilla::dom;

NS_IMPL_CYCLE_COLLECTION_CLASS(PresentationConnection)

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(PresentationConnection, DOMEventTargetHelper)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOwningConnectionList)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(PresentationConnection, DOMEventTargetHelper)
  tmp->Shutdown();
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mOwningConnectionList)
NS_IMPL_CYCLE_COLLECTION_UNLINK_END

NS_IMPL_ADDREF_INHERITED(PresentationConnection, DOMEventTargetHelper)
NS_IMPL_RELEASE_INHERITED(PresentationConnection, DOMEventTargetHelper)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(PresentationConnection)
  NS_INTERFACE_MAP_ENTRY(nsIPresentationSessionListener)
  NS_INTERFACE_MAP_ENTRY(nsIRequest)
NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)

PresentationConnection::PresentationConnection(nsPIDOMWindowInner* aWindow,
                                               const nsAString& aId,
                                               const nsAString& aUrl,
                                               const uint8_t aRole,
                                               PresentationConnectionList* aList)
  : DOMEventTargetHelper(aWindow)
  , mId(aId)
  , mUrl(aUrl)
  , mState(PresentationConnectionState::Connecting)
  , mOwningConnectionList(aList)
  , mBinaryType(PresentationConnectionBinaryType::Arraybuffer)
{
  MOZ_ASSERT(aRole == nsIPresentationService::ROLE_CONTROLLER ||
             aRole == nsIPresentationService::ROLE_RECEIVER);
  mRole = aRole;
}

/* virtual */ PresentationConnection::~PresentationConnection()
{
}

/* static */ already_AddRefed<PresentationConnection>
PresentationConnection::Create(nsPIDOMWindowInner* aWindow,
                               const nsAString& aId,
                               const nsAString& aUrl,
                               const uint8_t aRole,
                               PresentationConnectionList* aList)
{
  MOZ_ASSERT(aRole == nsIPresentationService::ROLE_CONTROLLER ||
             aRole == nsIPresentationService::ROLE_RECEIVER);
  RefPtr<PresentationConnection> connection =
    new PresentationConnection(aWindow, aId, aUrl, aRole, aList);
  if (NS_WARN_IF(!connection->Init())) {
    return nullptr;
  }

  if (aRole == nsIPresentationService::ROLE_CONTROLLER) {
    ControllerConnectionCollection::GetSingleton()->AddConnection(connection,
                                                                  aRole);
  }

  return connection.forget();
}

bool
PresentationConnection::Init()
{
  if (NS_WARN_IF(mId.IsEmpty())) {
    return false;
  }

  nsCOMPtr<nsIPresentationService> service =
    do_GetService(PRESENTATION_SERVICE_CONTRACTID);
  if(NS_WARN_IF(!service)) {
    return false;
  }

  nsresult rv = service->RegisterSessionListener(mId, mRole, this);
  if(NS_WARN_IF(NS_FAILED(rv))) {
    return false;
  }

  rv = AddIntoLoadGroup();
  if(NS_WARN_IF(NS_FAILED(rv))) {
    return false;
  }

  return true;
}

void
PresentationConnection::Shutdown()
{
  PRES_DEBUG("connection shutdown:id[%s], role[%d]\n",
             NS_ConvertUTF16toUTF8(mId).get(), mRole);

  nsCOMPtr<nsIPresentationService> service =
    do_GetService(PRESENTATION_SERVICE_CONTRACTID);
  if (NS_WARN_IF(!service)) {
    return;
  }

  DebugOnly<nsresult> rv = service->UnregisterSessionListener(mId, mRole);
  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "UnregisterSessionListener failed");

  DebugOnly<nsresult> rv2 = RemoveFromLoadGroup();
  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv2), "RemoveFromLoadGroup failed");

  if (mRole == nsIPresentationService::ROLE_CONTROLLER) {
    ControllerConnectionCollection::GetSingleton()->RemoveConnection(this,
                                                                     mRole);
  }
}

/* virtual */ void
PresentationConnection::DisconnectFromOwner()
{
  Unused << NS_WARN_IF(NS_FAILED(ProcessConnectionWentAway()));
  DOMEventTargetHelper::DisconnectFromOwner();
}

/* virtual */ JSObject*
PresentationConnection::WrapObject(JSContext* aCx,
                                   JS::Handle<JSObject*> aGivenProto)
{
  return PresentationConnectionBinding::Wrap(aCx, this, aGivenProto);
}

void
PresentationConnection::GetId(nsAString& aId) const
{
  aId = mId;
}

void
PresentationConnection::GetUrl(nsAString& aUrl) const
{
  aUrl = mUrl;
}

PresentationConnectionState
PresentationConnection::State() const
{
  return mState;
}

PresentationConnectionBinaryType
PresentationConnection::BinaryType() const
{
  return mBinaryType;
}

void
PresentationConnection::SetBinaryType(PresentationConnectionBinaryType aType)
{
  mBinaryType = aType;
}

void
PresentationConnection::Send(const nsAString& aData,
                             ErrorResult& aRv)
{
  // Sending is not allowed if the session is not connected.
  if (NS_WARN_IF(mState != PresentationConnectionState::Connected)) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }

  nsCOMPtr<nsIPresentationService> service =
    do_GetService(PRESENTATION_SERVICE_CONTRACTID);
  if(NS_WARN_IF(!service)) {
    AsyncCloseConnectionWithErrorMsg(
      NS_LITERAL_STRING("Unable to send message due to an internal error."));
    return;
  }

  nsresult rv = service->SendSessionMessage(mId, mRole, aData);
  if(NS_WARN_IF(NS_FAILED(rv))) {
    const uint32_t kMaxMessageLength = 256;
    nsAutoString data(Substring(aData, 0, kMaxMessageLength));

    AsyncCloseConnectionWithErrorMsg(
      NS_LITERAL_STRING("Unable to send message: \"") + data +
      NS_LITERAL_STRING("\""));
  }
}

void
PresentationConnection::Send(Blob& aData,
                             ErrorResult& aRv)
{
  if (NS_WARN_IF(mState != PresentationConnectionState::Connected)) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }

  nsCOMPtr<nsIPresentationService> service =
    do_GetService(PRESENTATION_SERVICE_CONTRACTID);
  if(NS_WARN_IF(!service)) {
    AsyncCloseConnectionWithErrorMsg(
      NS_LITERAL_STRING("Unable to send message due to an internal error."));
    return;
  }

  nsresult rv = service->SendSessionBlob(mId, mRole, &aData);
  if(NS_WARN_IF(NS_FAILED(rv))) {
    AsyncCloseConnectionWithErrorMsg(
      NS_LITERAL_STRING("Unable to send binary message for Blob message."));
  }
}

void
PresentationConnection::Send(const ArrayBuffer& aData,
                             ErrorResult& aRv)
{
  if (NS_WARN_IF(mState != PresentationConnectionState::Connected)) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }

  nsCOMPtr<nsIPresentationService> service =
    do_GetService(PRESENTATION_SERVICE_CONTRACTID);
  if(NS_WARN_IF(!service)) {
    AsyncCloseConnectionWithErrorMsg(
      NS_LITERAL_STRING("Unable to send message due to an internal error."));
    return;
  }

  aData.ComputeLengthAndData();

  static_assert(sizeof(*aData.Data()) == 1, "byte-sized data required");

  uint32_t length = aData.Length();
  char* data = reinterpret_cast<char*>(aData.Data());
  nsDependentCSubstring msgString(data, length);

  nsresult rv = service->SendSessionBinaryMsg(mId, mRole, msgString);
  if(NS_WARN_IF(NS_FAILED(rv))) {
    AsyncCloseConnectionWithErrorMsg(
      NS_LITERAL_STRING("Unable to send binary message for ArrayBuffer message."));
  }
}

void
PresentationConnection::Send(const ArrayBufferView& aData,
                             ErrorResult& aRv)
{
  if (NS_WARN_IF(mState != PresentationConnectionState::Connected)) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }

  nsCOMPtr<nsIPresentationService> service =
    do_GetService(PRESENTATION_SERVICE_CONTRACTID);
  if(NS_WARN_IF(!service)) {
    AsyncCloseConnectionWithErrorMsg(
      NS_LITERAL_STRING("Unable to send message due to an internal error."));
    return;
  }

  aData.ComputeLengthAndData();

  static_assert(sizeof(*aData.Data()) == 1, "byte-sized data required");

  uint32_t length = aData.Length();
  char* data = reinterpret_cast<char*>(aData.Data());
  nsDependentCSubstring msgString(data, length);

  nsresult rv = service->SendSessionBinaryMsg(mId, mRole, msgString);
  if(NS_WARN_IF(NS_FAILED(rv))) {
    AsyncCloseConnectionWithErrorMsg(
      NS_LITERAL_STRING("Unable to send binary message for ArrayBufferView message."));
  }
}

void
PresentationConnection::Close(ErrorResult& aRv)
{
  // It only works when the state is CONNECTED or CONNECTING.
  if (NS_WARN_IF(mState != PresentationConnectionState::Connected &&
                 mState != PresentationConnectionState::Connecting)) {
    return;
  }

  nsCOMPtr<nsIPresentationService> service =
    do_GetService(PRESENTATION_SERVICE_CONTRACTID);
  if(NS_WARN_IF(!service)) {
    aRv.Throw(NS_ERROR_DOM_OPERATION_ERR);
    return;
  }

  Unused << NS_WARN_IF(NS_FAILED(
    service->CloseSession(mId,
                          mRole,
                          nsIPresentationService::CLOSED_REASON_CLOSED)));
}

void
PresentationConnection::Terminate(ErrorResult& aRv)
{
  // It only works when the state is CONNECTED.
  if (NS_WARN_IF(mState != PresentationConnectionState::Connected)) {
    return;
  }

  nsCOMPtr<nsIPresentationService> service =
    do_GetService(PRESENTATION_SERVICE_CONTRACTID);
  if(NS_WARN_IF(!service)) {
    aRv.Throw(NS_ERROR_DOM_OPERATION_ERR);
    return;
  }

  Unused << NS_WARN_IF(NS_FAILED(service->TerminateSession(mId, mRole)));
}

bool
PresentationConnection::Equals(uint64_t aWindowId,
                               const nsAString& aId)
{
  return GetOwner() &&
         aWindowId == GetOwner()->WindowID() &&
         mId.Equals(aId);
}

NS_IMETHODIMP
PresentationConnection::NotifyStateChange(const nsAString& aSessionId,
                                          uint16_t aState,
                                          nsresult aReason)
{
  PRES_DEBUG("connection state change:id[%s], state[%" PRIx32
             "], reason[%" PRIx32 "], role[%d]\n",
             NS_ConvertUTF16toUTF8(aSessionId).get(), aState,
             static_cast<uint32_t>(aReason), mRole);

  if (!aSessionId.Equals(mId)) {
    return NS_ERROR_INVALID_ARG;
  }

  // A terminated connection should always remain in terminated.
  if (mState == PresentationConnectionState::Terminated) {
    return NS_OK;
  }

  PresentationConnectionState state;
  switch (aState) {
    case nsIPresentationSessionListener::STATE_CONNECTING:
      state = PresentationConnectionState::Connecting;
      break;
    case nsIPresentationSessionListener::STATE_CONNECTED:
      state = PresentationConnectionState::Connected;
      break;
    case nsIPresentationSessionListener::STATE_CLOSED:
      state = PresentationConnectionState::Closed;
      break;
    case nsIPresentationSessionListener::STATE_TERMINATED:
      state = PresentationConnectionState::Terminated;
      break;
    default:
      NS_WARNING("Unknown presentation session state.");
      return NS_ERROR_INVALID_ARG;
  }

  if (mState == state) {
    return NS_OK;
  }
  mState = state;

  nsresult rv = ProcessStateChanged(aReason);
  if(NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
  }

  if (mOwningConnectionList) {
    mOwningConnectionList->NotifyStateChange(aSessionId, this);
  }

  return NS_OK;
}

nsresult
PresentationConnection::ProcessStateChanged(nsresult aReason)
{
  switch (mState) {
    case PresentationConnectionState::Connecting:
      return NS_OK;
    case PresentationConnectionState::Connected: {
      RefPtr<AsyncEventDispatcher> asyncDispatcher =
        new AsyncEventDispatcher(this, NS_LITERAL_STRING("connect"), false);
      return asyncDispatcher->PostDOMEvent();
    }
    case PresentationConnectionState::Closed: {
      PresentationConnectionClosedReason reason =
        PresentationConnectionClosedReason::Closed;

      nsString errorMsg;
      if (NS_FAILED(aReason)) {
        reason = PresentationConnectionClosedReason::Error;
        nsCString name, message;

        // If aReason is not a DOM error, use error name as message.
        if (NS_FAILED(NS_GetNameAndMessageForDOMNSResult(aReason,
                                                         name,
                                                         message))) {
          mozilla::GetErrorName(aReason, message);
          message.InsertLiteral("Internal error: ", 0);
        }
        CopyUTF8toUTF16(message, errorMsg);
      }

      Unused <<
        NS_WARN_IF(NS_FAILED(DispatchConnectionCloseEvent(reason, errorMsg)));

      return RemoveFromLoadGroup();
    }
    case PresentationConnectionState::Terminated: {
      // Ensure onterminate event is fired.
      RefPtr<AsyncEventDispatcher> asyncDispatcher =
        new AsyncEventDispatcher(this, NS_LITERAL_STRING("terminate"), false);
      Unused << NS_WARN_IF(NS_FAILED(asyncDispatcher->PostDOMEvent()));

      nsCOMPtr<nsIPresentationService> service =
        do_GetService(PRESENTATION_SERVICE_CONTRACTID);
      if (NS_WARN_IF(!service)) {
        return NS_ERROR_NOT_AVAILABLE;
      }

      nsresult rv = service->UnregisterSessionListener(mId, mRole);
      if(NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }

      return RemoveFromLoadGroup();
    }
    default:
      MOZ_CRASH("Unknown presentation session state.");
      return NS_ERROR_INVALID_ARG;
  }
}

NS_IMETHODIMP
PresentationConnection::NotifyMessage(const nsAString& aSessionId,
                                      const nsACString& aData,
                                      bool aIsBinary)
{
  PRES_DEBUG("connection %s:id[%s], data[%s], role[%d]\n", __func__,
             NS_ConvertUTF16toUTF8(aSessionId).get(),
             nsPromiseFlatCString(aData).get(), mRole);

  if (!aSessionId.Equals(mId)) {
    return NS_ERROR_INVALID_ARG;
  }

  // No message should be expected when the session is not connected.
  if (NS_WARN_IF(mState != PresentationConnectionState::Connected)) {
    return NS_ERROR_DOM_INVALID_STATE_ERR;
  }

  if (NS_WARN_IF(NS_FAILED(DoReceiveMessage(aData, aIsBinary)))) {
    AsyncCloseConnectionWithErrorMsg(
      NS_LITERAL_STRING("Unable to receive a message."));
    return NS_ERROR_FAILURE;
  }

  return NS_OK;
}

nsresult
PresentationConnection::DoReceiveMessage(const nsACString& aData, bool aIsBinary)
{
  // Transform the data.
  AutoJSAPI jsapi;
  if (!jsapi.Init(GetOwner())) {
    return NS_ERROR_FAILURE;
  }
  JSContext* cx = jsapi.cx();
  JS::Rooted<JS::Value> jsData(cx);

  nsresult rv;
  if (aIsBinary) {
    if (mBinaryType == PresentationConnectionBinaryType::Blob) {
      RefPtr<Blob> blob =
        Blob::CreateStringBlob(GetOwner(), aData, EmptyString());
      MOZ_ASSERT(blob);

      if (!ToJSValue(cx, blob, &jsData)) {
        return NS_ERROR_FAILURE;
      }
    } else if (mBinaryType == PresentationConnectionBinaryType::Arraybuffer) {
      JS::Rooted<JSObject*> arrayBuf(cx);
      rv = nsContentUtils::CreateArrayBuffer(cx, aData, arrayBuf.address());
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
      jsData.setObject(*arrayBuf);
    } else {
      NS_RUNTIMEABORT("Unknown binary type!");
      return NS_ERROR_UNEXPECTED;
    }
  } else {
    NS_ConvertUTF8toUTF16 utf16Data(aData);
    if(NS_WARN_IF(!ToJSValue(cx, utf16Data, &jsData))) {
      return NS_ERROR_FAILURE;
    }
  }

  return DispatchMessageEvent(jsData);
}

nsresult
PresentationConnection::DispatchConnectionCloseEvent(
  PresentationConnectionClosedReason aReason,
  const nsAString& aMessage,
  bool aDispatchNow)
{
  if (mState != PresentationConnectionState::Closed) {
    MOZ_ASSERT(false, "The connection state should be closed.");
    return NS_ERROR_FAILURE;
  }

  PresentationConnectionCloseEventInit init;
  init.mReason = aReason;
  init.mMessage = aMessage;

  RefPtr<PresentationConnectionCloseEvent> closedEvent =
    PresentationConnectionCloseEvent::Constructor(this,
                                                   NS_LITERAL_STRING("close"),
                                                   init);
  closedEvent->SetTrusted(true);

  if (aDispatchNow) {
    bool ignore;
    return DOMEventTargetHelper::DispatchEvent(closedEvent, &ignore);
  }

  RefPtr<AsyncEventDispatcher> asyncDispatcher =
    new AsyncEventDispatcher(this, static_cast<Event*>(closedEvent));
  return asyncDispatcher->PostDOMEvent();
}

nsresult
PresentationConnection::DispatchMessageEvent(JS::Handle<JS::Value> aData)
{
  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(GetOwner());
  if (NS_WARN_IF(!global)) {
    return NS_ERROR_NOT_AVAILABLE;
  }

  // Get the origin.
  nsAutoString origin;
  nsresult rv = nsContentUtils::GetUTFOrigin(global->PrincipalOrNull(), origin);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  RefPtr<MessageEvent> messageEvent = new MessageEvent(this, nullptr, nullptr);

  messageEvent->InitMessageEvent(nullptr,
                                 NS_LITERAL_STRING("message"),
                                 false, false, aData, origin,
                                 EmptyString(), nullptr,
                                 Sequence<OwningNonNull<MessagePort>>());
  messageEvent->SetTrusted(true);

  RefPtr<AsyncEventDispatcher> asyncDispatcher =
    new AsyncEventDispatcher(this, static_cast<Event*>(messageEvent));
  return asyncDispatcher->PostDOMEvent();
}

nsresult
PresentationConnection::ProcessConnectionWentAway()
{
  if (mState != PresentationConnectionState::Connected &&
      mState != PresentationConnectionState::Connecting) {
    // If the state is not connected or connecting, do not need to
    // close the session.
    return NS_OK;
  }

  mState = PresentationConnectionState::Terminated;

  nsCOMPtr<nsIPresentationService> service =
    do_GetService(PRESENTATION_SERVICE_CONTRACTID);
  if (NS_WARN_IF(!service)) {
    return NS_ERROR_NOT_AVAILABLE;
  }

  return service->CloseSession(
    mId, mRole, nsIPresentationService::CLOSED_REASON_WENTAWAY);
}

NS_IMETHODIMP
PresentationConnection::GetName(nsACString &aResult)
{
  aResult.AssignLiteral("about:presentation-connection");
  return NS_OK;
}

NS_IMETHODIMP
PresentationConnection::IsPending(bool* aRetval)
{
  *aRetval = true;
  return NS_OK;
}

NS_IMETHODIMP
PresentationConnection::GetStatus(nsresult* aStatus)
{
  *aStatus = NS_OK;
  return NS_OK;
}

NS_IMETHODIMP
PresentationConnection::Cancel(nsresult aStatus)
{
  nsCOMPtr<nsIRunnable> event =
    NewRunnableMethod("dom::PresentationConnection::ProcessConnectionWentAway",
                      this,
                      &PresentationConnection::ProcessConnectionWentAway);
  return NS_DispatchToCurrentThread(event);
}
NS_IMETHODIMP
PresentationConnection::Suspend(void)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
PresentationConnection::Resume(void)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP
PresentationConnection::GetLoadGroup(nsILoadGroup** aLoadGroup)
{
  *aLoadGroup = nullptr;

  nsCOMPtr<nsIDocument> doc = GetOwner() ? GetOwner()->GetExtantDoc() : nullptr;
  if (!doc) {
    return NS_ERROR_FAILURE;
  }

  *aLoadGroup = doc->GetDocumentLoadGroup().take();
  return NS_OK;
}

NS_IMETHODIMP
PresentationConnection::SetLoadGroup(nsILoadGroup * aLoadGroup)
{
  return NS_ERROR_UNEXPECTED;
}

NS_IMETHODIMP
PresentationConnection::GetLoadFlags(nsLoadFlags* aLoadFlags)
{
  *aLoadFlags = nsIRequest::LOAD_BACKGROUND;
  return NS_OK;
}

NS_IMETHODIMP
PresentationConnection::SetLoadFlags(nsLoadFlags aLoadFlags)
{
  return NS_OK;
}

nsresult
PresentationConnection::AddIntoLoadGroup()
{
  // Avoid adding to loadgroup multiple times
  if (mWeakLoadGroup) {
    return NS_OK;
  }

  nsCOMPtr<nsILoadGroup> loadGroup;
  nsresult rv = GetLoadGroup(getter_AddRefs(loadGroup));
  if(NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  rv = loadGroup->AddRequest(this, nullptr);
  if(NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  mWeakLoadGroup = do_GetWeakReference(loadGroup);
  return NS_OK;
}

nsresult
PresentationConnection::RemoveFromLoadGroup()
{
  if (!mWeakLoadGroup) {
    return NS_OK;
  }

  nsCOMPtr<nsILoadGroup> loadGroup = do_QueryReferent(mWeakLoadGroup);
  if (loadGroup) {
    mWeakLoadGroup = nullptr;
    return loadGroup->RemoveRequest(this, nullptr, NS_OK);
  }

  return NS_OK;
}

void
PresentationConnection::AsyncCloseConnectionWithErrorMsg(const nsAString& aMessage)
{
  if (mState == PresentationConnectionState::Terminated) {
    return;
  }

  nsString message = nsString(aMessage);
  RefPtr<PresentationConnection> self = this;
  nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
    "dom::PresentationConnection::AsyncCloseConnectionWithErrorMsg",
    [self, message]() -> void {
      // Set |mState| to |PresentationConnectionState::Closed| here to avoid
      // calling |ProcessStateChanged|.
      self->mState = PresentationConnectionState::Closed;

      // Make sure dispatching the event and closing the connection are invoked
      // at the same time by setting |aDispatchNow| to true.
      Unused << NS_WARN_IF(NS_FAILED(
        self->DispatchConnectionCloseEvent(PresentationConnectionClosedReason::Error,
                                           message,
                                           true)));

      nsCOMPtr<nsIPresentationService> service =
        do_GetService(PRESENTATION_SERVICE_CONTRACTID);
      if(NS_WARN_IF(!service)) {
        return;
      }

      Unused << NS_WARN_IF(NS_FAILED(
        service->CloseSession(self->mId,
                              self->mRole,
                              nsIPresentationService::CLOSED_REASON_ERROR)));
    });

  Unused << NS_WARN_IF(NS_FAILED(NS_DispatchToMainThread(r)));
}